Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author.

BIOLOGICAL PHOSPHORUS REMOVAL

FROM A PHOSPHORUS RICH

DAIRY PROCESSING WASTEWATER

A thesis presented in partial fulfilment of the requirements

for the degree of

Doctor of Philosophy

In

Environmental Engineering

at

Massey University

Turitea Campus, Palmerston North,

New Zealand

PAUL O. BICKERS

2005

,\, • � ,_r

".� .. "--

i' o� . Massey University � COLLEGE OF SCIENCES

CANDIDATE'S DECLARATION

COLLEGE OF SCIENCES Private Bag 102904 North Shore Mail Centre Auckland New Zealand T 6494140800 extn 9522 F 6494418 181 http://sciences.massey.ac.nz

This is to certify that the research carried out for my Doctoral thesis entitled "Biological

Phosphorus Removal From a Phosphorus Rich Dairy Processing Wastewater" in the

Institute of Technology, Massey University, Palmertson North, New Zealand is my own

work and that the thesis material has not been used in part or in whole for any other

qualification.

Candidate'S Name Paul Oliver Bickers

Signature O'-/ .. ;�/;;r 1« �, /J .r, ; ,L j V - li._'<_.J

-Z_{!b tjotf

"�.,-�� ·l .... t -� f" . == � -: " :�;.'f., I. Massey University -i ". COLLEGE Of SCIENCES

SUPERVISOR'S DECLARATION

COLLEGE OF SCIENCES Private Bag 102904 North Shore Mail Centre Auckland New Zealand T 649 414 0800 extn 9522 F 649441 8181 http://sciences.massey.ac.nz

This is to certify that the research carried out for the Doctoral thesis entitled "Biological

Phosphorus Removal From a Phosphorus Rich Dairy Processing Wastewater" was

done by Paul Oliver Bickers in the Institute of Technology, Massey University,

Palmerston North New Zealand. The thesis material has not been used in part or in

whole for any other qualification, and I confirm that the candidate has pursued the

course of study in accordance with the requirements of the Massey University

regulations:

Supervisor's Name Rao Bhamidimarri

Signature

.. �"­.". . . 1;' Massey University � COLLEGE OF SCIENCES

CERTIFICATE OF REGULATORY COMPLIANCE

This is to certify that the research carried out in the Doctoral Thesis entitled

Biological Phosphorus Removal From A Phosphorus Rich Dairy Processing

Wastewater

COLLEGE OF SCIENCES Private Bag 102904 North Shore Mail Centre Auckland New Zealand T 64 9 414 OBOO extn 9522 F 649441 B1Bl http://sciences.massev.ac.nz

in the Institute Of Technology and Engineering at Massey University, New Zealand:

(a) is the original work of the candidate, except as indicated by appropriate

attribution in the text and/or in the acknowledgements;

(b) that the text, excluding appendices/annexes, does not exceed 100 000 words;

(c) all the ethical requirements applicable to this study have been complied with as

required by Massey University, other organisations and/or committees ___ _

which had a particular association

with this study, and relevant legislation.

Please insert Ethical Authorisation code(s) here if applicable ________ _

Candidate's Name: Paul O. Bickers

Signature: Pf�C(>�S supervisor'SNa�e]: R� ;hVl�mi

,

dimarri

Signature: !JI.I �f( I Date: '

.2f(t6(OV \

ABSTRACT

A phosphorus rich wastewater, typical of a dairy processing site producing milk

powder, was biologically treated in a continuous activated sludge reactor.

A l iterature review indicated there was a vast amount of information on the

mechanisms of the Enhanced Biological Phosphorus Removal (EBPR) process and

its application to domestic wastewaters, but little successful research on its application

to dairy processing wastewater.

The biodegradability of the wastewater organic fractions was assessed due to their

impact on the EBPR process. Continuous anaerobic fennentation tests were used to

detennine the concentration of volatile fatty acids that could be generated, as these are

required for successful EBPR. A fermenter hydraulic retention time of 1 2 hours and a

temperature of 35 °C generated the highest concentration of volatile fatty acids, with

an acidification rate of 65% (based on 0.451lm filtered COD).

To permit improved dissolved oxygen control and increased flexibility, a multi-zone

reactor was designed. A fermentation stage was also incorporated prior to the

activated sludge reactor. This reactor was operated with anaerobic, anoxic and aerobic

zones at an SRT of 1 0 days and stable biological phosphorus removal was achieved.

A maximum of 4 1 .5 mg P/L was removed and phosphorus release and PHA storage

occurred in both the anaerobic and anoxic zones. The soluble COD consumed in the

unaerated zones (anaerobic + anoxic) totalled 484 mg COD/L on the day of the zone

study (day 1 58) . The aerobic sludge phosphorus concentration averaged 7.0% mg

Plmg VSS after system optimisation. The anaerobic volume was doubled in order to

increase the anaerobic consumption of volatile fatty acids. This change increased the

amount of soluble COD consumption in the unaerated zones to 632 mg P/L after 40

days but did not result in a significant increase in biological phosphorus removal.

In the next senes of trials, the concentration of nitrogen in the wastewater was

decreased and the anoxic zone removed. This change did not improve the amount of

biological phosphorus removal , which was 35 mg P/L at an SRT of 1 0 days. The

effect of different sludge retention times was then investigated. Increasing the SRT to

11

1 5 days resulted in little change in phosphorus removal (34.5 mg P/L). Decreasing the

SRT to 5 days resulted in the loss of EBPR.

The medium term effect on the EBPR process by removing the fermentation stage

was also assessed using an AO configuration at an SRT of 1 0 days. The amount of

phosphorus removed decreased slightly after 34 days to 34 mg P/L, but the soluble

COD consumed in the anaerobic zone increased to 624 mg P/L.

It was concluded that a stable EBPR process could be established when treating a

dairy processing wastewater with a continuous activated sludge reactor. The

biological stability was sensitive to changes in the solids retention time and the

removal of the fermentation stage.

111

ACKNOWLEDGEMENTS

I wish to acknowledge Professor Rao Bhamidimarri for establishing thi s project and

encouraging me to undertake it and also his patience during this long process of

completion. I also wish to acknowledge the financial support and input of the New

Zealand Dairy Research Insitute (now Fonterra Reseach), especially Mike Donkin,

Jim Bamett and latterly John Russell and Joanna Shepherd. Their patience has also

been much appreciated.

The assistance of the technical staff of the Massey University Institute of Technology

has also been much appreciated. Without the input of Don McLean in the mechanical

workshop and Bruce Col ins in the electrical workshop, this project would not have

been possible as they made my experimental concepts a reality. Thanks very much

Don and Bruce. Thanks also to John Sykes for providing analytical assistance and

keeping the instruments functioning and to Anne-Marie Jackson for placing

consumables orders and finding equipment. Mention must be made of the golf

outings with Don and John that kept me partial ly sane. The companionship and

knowledge of Magnus Christensson during his two years working on this difficult

project was also invaluable.

The encouragement and support of Andy Shilton who completed his own thesis while

continuing a busy lecturing schedule has been much appreciated. Thanks mate.

Finally thanks to my family for their support. To my wife Fiona and o ur daughters

Sera and Amy for putting up with this whole process. As we have progressed through

marriage, having a family, changing cities and employment this study has always

been present, hopefully now we can look forward to more time together. Leana Hola!

Thanks also to my mother for her solid support as always, this thesis is dedicated to

her.

IV

Abstract

Acknowledgements

Table of Contents

List of Figures

List of Tables

TABLE OF CONTENTS

Abbreviations and Nomenclature

Chapter 1 : Introduction

1 . 1 The New Zealand Dairy Industry and Wastewater Management

1 .2 Phosphorus and the Dairy Industry

Page

11

IV

v

x

xvii

XXI

2

1 . 3 Biological Phosphorus Removal and dairy Processing Wastewater 2

1 .4 Research Approach 3

1 . 5 Specific Objectives 4

Chapter 2 : Literature Review 6

2 . 1 Phosphorus and the Environment 6

2 .2 Chemical and Biological Phosphorus Removal Options 7

2.2. 1 Chemical 7

2.2 .2 Biological 8

2 .3 Enhanced Biological Phosphorus Removal (EBPR) 9

2.3 . 1 Principles of EBPR 9

2 .3 .2 Biochemical Principles of EBPR 1 0

2 .3 .3 Microbiology of EBPR 1 4

2 .3 .4 Substrate Influences on EBPR 1 4

2 .3 .5 Influences of Substrates on the Microbial Population 1 7

2 .4 Biological Phosphorus Removal Systems 1 9

v

2 .4. 1 EBPR Systems without Nitrogen Removal 20

2.2.2 EBPR Systems with Nitrogen Removal 20

2.4.3 Factors Affecting EBPR System Perfonnance 23

2.5 Dairy Processing Wastewater 23

2 .5 . 1 Characteristics o f Dairy Processing Wastewater 24

2 .5. 1 . 1 Nitrogen 26

2.5 . 1 .2 Phosphorus 28

2 .5 .2 Synthetic Dairy Processing Wastewater 29

2.6 Biological Phosphorus Removal from Dairy Processing Wastewater 30

2.7

2 .8

Chapter 3 :

3 . 1

3 .2

Fennentation of Dairy Processing Wastewater

Summary

Analytical and Experimental Methodology

Introduction

Analytical Methodology

3 .2 . 1 Total Suspended Solids (TSS) and Volatile Suspended Solids (VSS)

3 .2 .2 Chemical Oxygen Demand (COD)

3 .2 .3 Total Phosphorus (TP)

3 .2 .5 Total Kjeldahl Nitrogen (TKN)

3 .2.6 Ammonia

3 .2 .7 Glycogen

3 .2 .8 Poly-B-hydroxyalkanoate (PHA)

3 .2 .9 Volatile Fatty Acids (VFA's)

3 .2 . 1 0 Dissolved Oxygen (DO) and Oxygen Uptake Rate (OUR and SOUR)

VI

33

35

36

36

36

36

38

39

40

4 1

4 1

4 1

42

44

44

3 .2 . 1 1 Sludge Volume Index 45

3 .2 . 1 2 pH Measurement 46

3 .3 Laboratory -Scale Reactors 46

3 .3 . 1 Preliminary AAO Reactor System 46

3 .3 .2 Preliminary MUCT Reactor System 50

3 .3 . 3 Zoned Activated Sludge Reactor System 52

3 .3 .4 Fermentation reactor 55

3 .3 .5 Laboratory Pumps 55

3 .3 .6 Reactor System Steady State 55

3 .4 Synthetic Wastewater Composition 57

Chapter 4 : Wastewater Characterisation and Fennentation Studies 60

4 . 1 Introduction 60

4.2 Synthetic Dairy Processing Wastewater 60

4.3 COD Fractionation of Waste water 6 1

4.3 . 1 Aerobic Batch Tests 63

4.3 .2 Anoxic Batch Tests 66

4.4 Fermentation of Dairy Processing Wastewater 72

4.4. 1 Fermentation Studies 74

4.5 Discussion 77

4.6 Conclusions 78

Chapter 5 : Preliminary EBPR Reactor Studies 79

5 . 1 Introduction 79

5 .2 AAO Configuration 79

5.2. 1 Reactor Operation 8 1

5 .2.2 Nitrogen Removal 84

Vll

5 .2.3 Phosphorus Removal 86

5 .2 .4 Discussion 87

5.3 MU CT Configuration 89 5 .3 . 1 Reactor Operation 90

5 .3 .2 Discussion 95

5.4 Conclusions 97

Chapter 6: Combined Nitrogen and Phosphorus Removal - AAO Zoned Reactor Studies 98

6 . 1 Introduction 98

6.2 Reactor System 98

6 .3 Fermenter Operation 1 01

6.4 Zoned BNR Reactor Operation 1 03

6.4. 1 Zone Analysis 1 09

6.4.2 Batch Test 1 1 5

6.5 Extended Anaerobic Retention Time Test 1 20

6 .5 . 1 Extended Anaerobic HRT AAO Reactor (EAAO) Zone Study 1 20

6.5 .2 EAAO Anaerobic Batch Test 1 25

6.6 Discussion 1 28

6 .7 Conclusion 1 36

Chapter 7 : Phosphorus Removal-AO Zoned Reactor Studies 1 3 8

7 . 1 Introduction 1 3 8

7 .2 Reactor System 1 39

7 .3 Fermenter Operation 1 42

7.4 1 0 Day SRT AO Reactor Zone Study 1 44

7.4 . 1 Batch Test 1 5 1

viii

7 .5 AO Reactor Operation at an S RT of 15 days 1 54

7 .5 . 1 Reactor Operation 1 54

7 .5 .2 Zone Analysis 1 59

7 .5 .3 Batch Test 1 66

7 .6 AO Reactor Operation at an SRT of 5 days 1 69

7.6. 1 Reactor Operation 1 69

7.6.2 Zone Study 1 74

7 .7 Discussion 178

7 .8 Conclusions 1 83

Chapter 8 : Influences on Phosphorus Removal 1 85

8 . 1 Introduction 1 83

8.2 Phosphorus Precipitation 1 85

8 .3 Cessation of Extemal Fennentation - Medium Term Effects 1 90

8.3 . 1 Batch Test 1 97

8 .4 Nutrient Requirements 1 99

8 .5 Discussion 203

8 .6 Conclusion 205

Chapter 9 : Final Discussion and Conclusions 207

9. 1 Introduction 207

9.2 Phosphorus Removal 208

9.3 Reactor System Comparisons 209

9.4 Full-Scale Implications 2 1 3

9.5 Future Research 215

9 .6 Recommendations 2 1 6

Chapter 1 0: Appendix 2 1 8

IX

Chapter 1 1 : References 229

Chapter 2

Figure 2 . 1 :

Figure 2.2:

Figure 2 . 3 :

Figure 2 .4:

Figure 2 .5 :

Figure 2 .6 :

Figure 2 .7 :

F igure 2 . 8 :

Figure 2 .9 :

Figure 2 . 1 0:

Chapter 3

Figure 3 . 1 :

Figure 3 .2 :

Figure 3 . 3 :

Figure 3 .4 :

Figure 3 . 5 :

Figure 3 .6 :

Figure 3 .7:

LIST OF FIGURES

Biological Effects of Eutrophication

(Queens University Belfast, 2003).

Page

6

Profiles of soluble BOO and phosphorus during the EBPR process. 1 0

Schematic diagrams for the behaviour proposed by the

ComeaulWentzel model unanaerobic (a) and aerobic conditions (b). 1 2

Schematic diagrams of the biochemical mechanisms proposed by

the Mino model under anaerobic (a) and aerobic conditons (b). 1 3

EBPR system without nitrogen removal (AO).

AAO system or 3 -stage modified Bardenpho.

Modified (5-stage) Bardenpho, Phoredox.

UCT process.

Modified UCT.

SBR sequencing for biological phosphorus removal.

Example of GC chromatogram for PHB and PHV analysis.

Schematic of OUR measurement technique.

Schematic of AAO laboratory activated sludge system.

Picture of initial AAO laboratory activated sludge system.

Schematic of Modified UCT laboratory activated sludge system.

Schematic of improved laboratory zoned reactor system.

Zoned reactor system showing clarifier and stirrer, DO control

System and temperature control unit.

20

2 1

2 1

22

22

23

44

45

48

49

5 1

53

54

Figure 3 . 8 : Mixed liquor contents of zoned reactor system. 54

Figure 3 .9: Schematic of fermenter process. 56

Figure 3 . 1 0 : Photo of fermenter system showing 40C synthetic wastewater

Storage refrigerator on the right and fennented wastewater

refrigerator on the left.

x

57

Chapter 4

Figure 4. 1 : RBCOD detennination using aerobic batch test method for

Synthetic dairy processing wastewater (S/X=0.05). 65

Figure 4.2: RBCOD detennination using aerobic batch test method for

Synthetic dairy processing wastewater (S/X=0. 1 2). 66

Figure 4.3 : Anoxic batch test NUR graph for four different substrates. 69

Figure 4.4: Anoxic batch test comparison for acetate and synthetic dairy

processing wastewater. 7 1

Figure 4.5 : The percentage of each VF A as a fraction of the total VF A COD. 75

Chapter 5

Figure 5. 1 : AAO activated sludge preliminary lab-scale system. 80

Figure 5 .2 : TSS concentration in each zone. 8 1

Figure 5 .3 : Zone VSS/TSS ratio' s during AAO system operation. 82

Figure 5.4: Variation in the SVI and the effluent TSS during AAO

system operation. 82

Figure 5 .5 : Soluble COD concentrations in each zone. 84

Figure 5 .6 : Ammonia concentrations in the aerobic zone and effluent. 85

Figure 5 .7 : Nitrate concentrations in each zone. 85

Figure 5.8: Soluble phosphorus (P04-P) concentration in each zone. 86

Figure 5 .9: P release in anaerobic and anoxic zones based on both

total influent phosphorus and the soluble influent phosphorus. 86

Figure 5 . 1 0: Modified UCT activated sludge lab-scale system for

treatment of synthetic dairy processing wastewater. 90

Figure 5 . 1 1 : TSS concentration in each zone for the MUCT system. 9 1

Figure 5 . 1 2 : COD concentration in each zone for the MUCT system. 92

Figure 5 . 1 3 : Anaerobic zone total and soluble COD consumption. 92

Figure 5 . 1 4 : Ammonia concentration in each zone for the MUCT system. 93

Figure 5 . 1 5 : NOx-N (Nitrate+Nitrite) concentrations in each zone

for the M UCT system. 94

Figure 5. 1 6: Orthophosphate (P04-P) concentrations in each zone

for the MUCT system. 94

Figure 5 . 1 7 : Phosphorus fractionation anaerobic batch test. 96

Xl

Chapter 6

Figure 6 . 1 : Schematic of laboratory treatment system. 99

Figure 6 .2 : Zoned l aboratory-scale activated sludge EBPR

AAO reactor system. 1 00

Figure 6 .3 Influent fermentation system. 1 0 1

Figure 6.4: COD profile during reactor operation in fermenter feed

and fermenter effluent. 1 02

Figure 6 .5 : VF A COD fractionation, total VF A COD and

% acidification of fermenter effluent. 1 02

Figure 6.6 : TSS profile during zoned AAO reactor operation. 1 04

Figure 6 .7 : COD profile during reactor operation in the anaerobic,

anoxic and last aerobic zone. 1 05

Figure 6 .8 : SVI variation during reactor operation. 1 05

Figure 6.9: Effluent nitrate concentrations during the reactor operation. 1 06

Figure 6 . 1 0: Phosphorus concentrations during the reactor operation. 1 07

Figure 6. 1 1 : Sludge phosphorus concentration in the final aerobic zone

during the reactor operation. 1 07

Figure 6. 1 2 : phosphorus removal during the reactor operation,

based on both the fermented effluent total phosphorus (TP)

and soluble phosphorus (P04-P). 1 08

Figure 6. 1 3 : Anaerobic zone PHA, PHB and PHV concentration during

the reactor operation. 1 08

Figure 6. 1 4 : TSS concentration and VSS/TSS ratio for each zone on day 1 58 . 1 1 1

Figure 6 . 1 5 : Soluble COD and P04-P decrease through each zone on day 1 58 . 1 1 1

Figure 6. 1 6 : Net phosphorus uptake in each zone (negative uptake means

phosphorus release). 1 1 2

Figure 6 . 1 7 : Biomass phosphorus content relative to the soluble P04-P

concentration in each zone. 1 1 2

Figure 6. 1 8: Nitrate and nitrite zone concentrations for each zone on day 1 58 . 1 1 3

Figure 6. 1 9 : Total PHA, PHB, PHV and glycogen sludge concentrations. 1 1 3

Figure 6.20: OUR uptake rates (OUR) and specific oxygen uptake rates

(SOUR) in each aerobic zone. 1 1 4

Figure 6.2 1 : Phosphorus release/uptake and acetate uptake during the

XIl

Figure 6.22:

Figure 6.23 :

Figure 6.24 :

Figure 6.25 :

Figure 6.26:

Figure 6.27:

Figure 6.28 :

Figure 6.29:

Figure 6.30:

Figure 6.3 1 :

Figure 6.32 :

Chapter 7

Figure 7 . 1 :

Figure 7.2:

Figure 7.3

Figure 7.4:

Figure 7 .5 :

Figure 7.6:

Figure 7 .7 :

Figure 7 .8 :

batch test with acetate as sole carbon source.

Specific oxygen uptake rate (SOUR) and phosphorus

during release/uptake during batch test.

VSS/TSS ratio and phosphorus release/uptake during batch test.

Glycogen, sludge phosphorus content and soluble phosphorus

profiles during batch test.

EAAO system TSS concentrations and VSS/TSS ratio profiles.

EAAO system soluble COD and soluble phosphate zone

concentrations.

EAAO system net phosphate uptake profiles (negative uptake

denotes phosphate release).

EAAO system biomass phosphorus content relative to soluble

phosphate concentrations.

EAAO system nitrate and nitrite concentrations.

Extended anaerobic zone system nitrate and nitrite concentrations.

Anaerobic batch test using sludge from EAAO system.

Theoretical phosphorus removed as a function of sludge

phosphorus concentration for individual mixed liquor VSS

concentrations for a reactor at an SRT of days.

Schematic of laboratory treatment system.

Zoned laboratory-scale AO activated sludge EBPR

reactor system.

1 1 6

1 1 8

1 1 8

1 1 9

1 2 1

1 22

1 23

1 23

1 24

1 25

1 28

1 30

1 4 1

1 4 1

F ermenter feed and effluent COD profile during reactor operation 1 43

VF A COD fractionation, total VF A COD and % acidification of

fermenter effluent.

Zone profiles of TSS, VSS and the VSS/TSS ratio for the 10 day SRT AO zoned reactor.

Zone profiles of soluble COD and P04-P for the

1 0 day SRT AO zoned reactor.

1 43

1 45

1 45

P04-P uptake for each zone for the 1 0 day SRT AO zoned reactor. 1 47

Soluble P04-P and sludge phosphorus profiles for each zone

for the 1 0 day SRT AO reactor. 1 48

Xlll

Figure 7 .9 : Zone nitrate concentrations for each zone for

the 1 0 day SRT AO reactor. 1 49

Figure 7 . 1 0 : SOUR and OUR profiles for each zone of 1 0 days AO reactor. 1 49

Figure 7 . 1 1 : Acetate COD and P04-P profiles during the batch test. 1 52

Figure 7. 1 2 : Sludge phosphorus content and VSS/TSS variation during

batch test at 0, 300 and 600 minutes. 1 53

Figure 7. 1 3 : SOUR and OUR profiles during thes batch test aerobic phase. 1 53

Figure 7. 1 4: TSS and VSS/TSS profiles during 1 5 day SRT reactor operation. 1 55

Figure 7. 1 5 : Soluble COD profiles of anaerobic zone and final aerobic zones

for 1 5 day SR T reactor operation. 1 55

Figure 7 . 1 6 : The amount of soluble COD and VF A COD consumed in the

anaerobic zone and the % of the available COD and VF A

consumed within the anaerobic zone for 1 5 day SRT reactor. 1 56

Figure 7. 1 7: SVI variations during the 1 5 day SRT Aa reactor operation. 1 57

Figure 7 . 1 8: Effluent nitrate concentrations during reactor operation

at an S RT of 1 5 days. 1 57

Figure 7 . 1 9: Soluble phosphorus concentrations in the anaerobic zone

and final aerobic zone during 1 5 day SRT reactor operation. 1 58

Figure 7 .20: Sludge phosphorus concentration in the final aerobic zone. 1 59

Figure 7 .2 1 : TSS, VSS and VSS/TS S ratio's for each zone

for 1 5 day AO reactor. 1 60

Figure 7.22: Soluble COD and P04-P profiles for each zone for

1 5 day SRT AO reactor. 1 6 1

Figure 7.23 : Phosphorus uptake in each zone for 1 5 day SRT AO reactor. 1 6 1

Figure 7.24: Sludge phosphorus content and P04-P concentrations for

each zone for the 1 5 day SRT reactor. 1 62

Figure 7.25 : Nitrate concentrations in each zone for the

1 5 day SRT AO reactor. 1 62

Figure 7.26: PHB, PHV, total PHA and glycogen concentrations for each

zone for the 1 5 day SR T AO reactor. 1 63

Figure 7 .27: SOUR and OUR rates for each zone for the 1 5 day

S R T A 0 reactor. 1 64

Figure 7 .28 : Soluble COD and P04-P profiles during batch test for

XIV

15 day SRT reactor. 1 66

Figure 7 .29: S ludge phosphorus content and VSS/TSS variations

during 1 5 day mixed liquor batch test. 1 67

Figure 7.30: PHB, PHV, total PHA, glycogen and SOUR profiles

during batch tests for 1 5 day S RT reactor. 1 68

Figure 7.3 1 : TSS, VSS and VSS/TSS ratio' s for the anaerobic zone

and the final aerobic during the 5 day SRT AO reactor operation. 1 70

Figure 7.32: Soluble COD for the anaerobic zone and the final aerobic

zone during the 5 day SRT AO reactor operation. 1 70

Figure 7 .33 : Total VF A COD concentration in the anaerobic zone, the amount

of VFA COD consumed within the anaerobic zone for 5 day

SRT AO reactor. 1 7 1

Figure 7.34: SVI variation during the operation of the 5 day SRT AO reactor. 1 72

Figure 7 .35 : Anaerobic and aerobic P04-P concentrations and the amount of

Anaerobic zone P-release during the operation of the 5 day

SRT AO reactor. 1 72

Figure 7 .36 : Final aerobic zone sludge phosphorus content during the

operation of the 5 day SRT AO reactor. 1 73

Figure 7 .37 : Final zone nitrate concentration during the operation of the

5 day SRT AO reactor. 1 73

Figure 7.3 8 : TSS, VSS and VSS/TSS ratio in each zone for reactor

operated at an SRT of 5 days. 1 75

Figure 7.39: Soluble COD and P04-P concentration in each zone for AO

Zoned reactor operated at an SRT of 5 days. 1 76

Figure 7.40: Anaerobic zone phosphorus uptake in each zone for AO zoned

Reactor operated an SR T of 5 days. 1 76

Figure 7 .4 1 : Final aerobic zone sludge phosphorus content and P04-P

for zones of AO reactor operated at an SRT of 5 days. 1 77

Figure 7 .42: Nitrate in each zone of AO reactor operated at an SRT of 5 days. 1 75

Figure 7.43: SOUR and OUR zone profiles for AO reactor operated

at an S R T of 5 days. 1 77

F igure 7 .44: Phosphorus release (negative) and uptake (positive) rates for

Each AO system zone study. 1 82

xv

Chapter 8

Figure 8 . 1 :

Figure 8 .2 :

Figure 8 . 3 :

Figure 8 .4:

Figure 8 .5 :

Figure 8 .6 :

Figure 8 .7 :

Figure 8 . 8 :

Figure 8 .9 :

Figure 8 . 1 0 :

Figure 8 . 1 1 :

Chapter 9

Figure 9. 1 :

Figure 9 .2 :

Figure 9.3:

Figure 9.4:

Zone pH values for each zone study.

Soluble calcium values for zones 1 , 5 and 1 0 for the 1 5 day SRT

AO system (the total calcium concentration value in the

effluent is 1 5 .3 mg/L).

Soluble effluent phosphorus concentration over a 34 day period

for an AO configured reactor fed unfermented wastewater.

TSS, VSS and VSS/TSS zone profiles for Aa system treating

unfermented wastewater.

Soluble COD and phosphorus profiles for AO system treating

unfermented wastewater.

Anaerobic zone phosphorus uptake for non-fermented system.

Sludge phosphorus content for each zone.

Zone P HB, PHV and PHA concentrations.

SOUR and OUR respiration rates for each zone.

Soluble COD and P04-P profiles during batch test for

non-fermented system.

Concentrations of magnesium, calcium and potassium for zones

1 , 5 and 1 0 at the time of the 1 5 day Aa system zone study.

The total phosphorus removed in each system at the time

of the zone study.

Total unaerated zone phosphorus release and anaerobic zone only

phosphorus release relative to the unaerated fraction.

The relationship of the soluble COD consumption in the unaerated

zones and overall phosphorus removed relative to the unaerated

zone HRT (actual) for 1 0 day SRT reactors.

The change in Y P04 determined from acetate batch tests relative

1 89

1 89

1 90

1 94

1 93

1 94

1 95

1 95

1 94

1 97

202

2 1 0

2 1 1

2 1 1

to the continuous reactor total soluble consumption in the unaerated

zones. 2 1 3

XVI

Chapter 2

Table 2 . 1 :

Table 2.2 :

Table 2.3 :

Table 2.4:

Table 2 .5 :

Table 2 .6 :

Chapter 3

Table 3 . 1 :

Table 3 .2 :

Table 3 . 3 :

Table 3 .4:

Table 3 . 5 :

Chapter 4 Table 4.1:

Table 4.2:

Table 4 .3 :

Table 4.5

LIST OF TABLES

Precipitation reactions of phosphorus with lime, alum and

iron Fe (III)

Summary of molar ratios during anaerobi c and aerobic periods

for various organic substrates (from Comeau et al. , 1 987).

Ratios of phosphorus released and VF A consumed under

anaerobic conditions (from Abu-gharrarah and Randell, 1991).

Chemical characteristics of whole milk (Danalewich et al., 1998)

Chemical characteristics of dairy processing wastewaters.

A verage values of parameters are given along with either the

range of values or maximum value shown in brackets ( ).

Synthetic wastewater composition and characteristics as used

by Leonard ( 1 996).

Retention times in respective zones of laboratory AAO system.

Hydraulic retention times in respective zones of laboratory

MU CT system.

Synthetic wastewater recipe with COO/TKN ratio of 28 .

Recipe for synthetic wastewater with COD/TKN ratio of 32 .

Milk powder characteristics according to the manufacturer

(Anchor Milk Products Ltd, N .Z.).

Synthetic dairy processing wastewater recipe.

Synthetic dairy processing wastewater chemical and physical

characteristics.

NUR batch test parameters

NUR gradients for each substrate used in the anoxic batch test.

XVll

Page

8

1 6

1 7

25

27

3 1

47

50

58

58

59

6 1

62

68

69

Table 4.6 :

Table 4.7 :

Table 4 .8 :

Chapter 5

Table 5 . 1 :

Table 5 .2 :

Table 5 . 3 :

Table 5 .4 :

Table 5 .5 :

Chapter 6

Table 6. 1 :

Table 6 .2 :

Table 6 .3 :

Table 6.4:

Table 6 .5 :

Table 6.6:

Table 6.7:

Table 6.8 :

NUR gradients for each substrate used in second anoxic batch test. 7 1

RBCOD fraction and yield coefficients from the study

and literature.

Operating parameters and analytical data from the four different

fermenter operations.

Retention time in respective zones oflaboratory AAO system.

A verage analytical parameters for each zone during operation

of AAO lab-scale configuration.

Hydraulic retention times in respective zones of laboratory

MU CT system.

Average analytical parameters for each zone during operation

of MUCT lab-scale configuration.

Phosphorus fractionation of aerobic sludge sample (Day 35) .

Reactor system operational parameters.

Volume, number of individual zones and the HRT in the

anaerobic, anoxic and aerobic steps with the overall HRT.

Fermented wastewater VF A COD concentrations and percent

of total VF A COD and soluble COD« o45�m).

Individual zone parameters for AAO configuration.

Analytical parameters at time 0, 1 80, and 660 minutes for the

batch test for 1 0 day SRT AAO system. Glycogen concentration

is given for 420 minutes instead of 600 minutes.

Individual zone parameters for EAAO configuration.

Anaerobic and anoxic COD and VF A consumption and

phosphorus release values for the single anaerobic zone AAO

system (AAO) and for the extended anaerobic zone AAO system

(EAAO) . Anaerobic/anoxic phase stoichiometric constants from AAO

and EAAO zone studies and for both batch test of mixed liquor.

XVlll

72

76

80

89

90

95

97

99

1 00

1 03

1 1 7

1 1 9

1 26

1 3 1

1 34

Chapter 7

Table 7. 1 :

Table 7 .2 :

Table 7 .3

Table 7 .4 :

Table 7 .5 :

Table 7 .6 :

Table 7 .7 :

Table 7 .8 :

Table 7 .9 :

Table 7. 1 0 :

Table 7 . 1 1 :

Table 7 . 1 2 :

Synthetic dairy processing wastewater recipe used in the AO

zoned reactor studies.

Modified low nitrogen synthetic dairy processing wastewater

chemical and physical characteristics.

AO reactor system operational parameters.

Average fermented wastewater average VFA COD concentrations

and proportions of total VF A and total CODO.45ilm•

Fermenter Effluent and anaerobic zone (zone 1 ) individual short

chain VF A COD concentrations, the % oftotal VF A COD and

the % consumption of anaerobic zone individual VF A

based on fermenter effluent VF A concentrations.

Individual zone paramters for AO configuration at an SRT

of 1 0 days.

Analytical parameters at time 0, 300 and 600 minutes for

batch test using mixed liquor of AO system operated at an

S RT of 1 0 days.

Individual zone parameters for AO configuration at an SRT

of 1 5 days.

Analytical parameters at time 0, 1 80 and 420 minutes for

batch test using mixed liquor of AO system operated at an

SRT of 1 5 days. Except OUR and SOUR are given for 2 1 0

minutes instead of 1 80 minutes.

Individual zone parameters for AO configuration at an SRT

of 5 days.

Summary of anaerobic zone parameters during zone studies,

except for P removed and %mg P/mg VSS that relate to final

aerobic zone (zone 1 0).

Stoichiometric constants from each zone study and batch test

for the AO systems.

XIX

1 39

1 39

1 42

1 44

1 46

1 50

1 54

1 65

1 69

1 79

1 80

1 8 1

Chapter 8

Table 8 . 1 :

Table 8 .2 :

Table 8 .3 :

Table 8 .4 :

Table 8 . 5 :

Chapter 9

Chapter 10

Table 1 0. 1 :

Table 1 0.2 :

Table 1 0. 3 :

Table 1 0.4:

Table 1 0.5:

Table 1 0.6 :

Table 1 0.7 :

Table 1 0. 8 :

Table 1 0.9 :

Table 1 0. 1 0:

Table 1 0. 1 1 :

Characteristics of synthetic wastewater immediately before

entry to zoned reactor.

Individual and total VF A concentrations.

Individual zone parameters for non�fermented wastewater

AO configuration at an SRT of 1 0 days.

Analytical parameters at time 0, 240 and 480 minutes for the

batch of the unfermented 1 0 day SRT AO system.

Amount of magnesium, potassium and calcium release in the

anaerobic zone and the ratio of each cation to both phosphorus

release and uptake.

No Tables

Aerobic Readily Biodegradable Test Data, SIX ratio of 0.05

Aerobic Readily Biodegradable Test Data, SIX ratio of 0. 1 2

Anoxic Readily Biodegradable Test (SIX ratio of 0.03)

Anoxic Readily Biodegradable Test (SIX ratio of 0.08)

AAO Continuous Reactor Data - Unfermented Wastewater

MUCT Continuous Reactor Data - Unfermented Wastewater

Zoned AAO System - Fermented Wastewater

AAO Reactor Fermented Wastewater VFA Concentrations

Fermenter Operation during AO System Operation ( 1 5 day SRT)

1 5 Day SRT AO Reactor Operation

5 Day SRT AO Reactor System

xx

1 9 1

1 93

1 98

1 99

202

2 1 6

2 1 7

2 1 7

2 1 8

2 1 9

220

22 1

223

224

224

225

AAO

AO

ASM I

ASM2

BNR

BOD

COD

DO

EBPR

GAO

HRT

MLSS

MLVSS

MUCT

NUR

OUR

P

PAO

PHA

PHB

PHV

RAS

RBCOD

SA

SBCOD

SCVFA

SF

SII

SOUR

SRT

ABBREVIATIONS AND NOMENCLATURE

Anaerobic-Anoxic-Oxic

Anaerobic-Oxic

Activated Sludge Model No. 1

Activated Sludge Model No. 2

Biological Nutrient Removal

Biochemical Oxygen Demand (mg/L)

Chemical Oxygen Demand (mg/L)

Dissolved Oxygen (mg/L)

Enhanced Biological Phosphorus Removal

Glycogen Accumulating Organisms

Hydraulic Retention Time (d)

Mixed Liquor Suspended Solids

Mixed Liquor Volatile Suspended Solids

Modified University of Cape Town

Nitrate Uptake Rate

Oxygen Uptake Rate

Phosphorus

Polyphosphate Accumulating Organisms

Poly-p hydroxyalkanoates

Poly-p hydroxybutyric Acid

Poly-p hydroxyvaleric Acid

Return Activated Sludge

Readily Biodegradable Chemical Oxygen Demand

Fermentation Products as Acetate Equivalents (mg/L)

Slowly Biodegradable Chemical Oxygen Demand

Short Chain Volatile Fatty Acids

Fermentable Readily Biodegradable Substrates (mg/L)

Inert Soluble Substrate (mg/L)

Specific Oxygen Uptake Rate

Sludge Retention Time (d)

XXI

SSI Readily Biodegradable Substrate (mg/L)

SVI Sludge Volume Index (mllg)

SIX Substrate to Biomass Ratio

TKN Total Kjehldahl Nitrogen (mg/L)

TSS Total Suspended Solids (mg/L)

UCT University of Cape Town

VFA Volatile Fatty Acids

VSS Volatile Suspended Solids (mg/L)

XS1 S lowly Biodegradable Substrate (mg/L)

Y H Heterotrophic Yield Coefficient (mg Cell COD/mg COD consumed)

Y HO Anoxic Yield Coefficient (mg Cell COD/mg COD Consumed)

YP04 Ratio of Phosphorus Released to COD consumed (mg P/mg COD)

XXll